As a wood-type golf club head such as a driver and a fairway wood, a metallic hollow golf club head has been used widely. Generally, the hollow wood-type golf club head comprises a face part for hitting a ball, a crown part constituting the top surface portion of the golf club head, a sole part constituting the bottom surface portion of the golf club head, a side part constituting the side surface portions on the toe side, back side, and heel side of the golf club head, and a hosel part. In this hosel part, a shaft is inserted and fixed by an adhesive or the like.
As a metal forming the hollow golf club head, an aluminum alloy, stainless steel, or titanium alloy has been used, and especially titanium alloy has been used widely in recent years.
Japanese Unexamined Patent Application Publication No. 11-216203 and Japanese Unexamined Patent Application Publication No. 2004-41376 disclose a golf club head in which the thickness on the front edge side along the face part of the sole part is increased. In FIG. 2 of Japanese Unexamined Patent Application Publication No. 11-216203, this thick part is provided throughout the whole of the front edge of the sole part, and in FIG. 4 thereof, the thick part is provided on the toe side and the heel side. In Japanese Unexamined Patent Application Publication No. 2004-41376, the thick part is provided throughout the whole of the front edge of the sole part. Also, in this publication, the golf club head is formed by a head body and a face plate welded to the head body.